The objectives of this project are to 1) evaluate the effects of disease on the phagocytic cell, 2) determine the function and character of circulating suppressors of granulopoiesis, chemotaxis, and polymorphonuclear leukocyte (PMN) antibody dependent cell to cell cytotoxicity (ADCCC), which we find prevalent in anergic patients with severe systemic disease and, 3) to define the role of the PMN in the enhancement of mitogen induced lymphocyte stimulation. These parameters will be investigated using a modification of the Boyden technique for chemotaxis, the soft agar technique for culturing bone marrow cells, the Cr 51 release assay for detecting antibody dependent cell to cell cytotoxicity using both isolated PMN and lymphocytes, the erythrocyte rosetting technique for assaying Fc and C3b receptors, mitogen induced lymphocyte stimulation, and the chemotaxis technique for isolating purified human peripheral blood PMN. Experiments will use these techniques along with separation technique to isolate the serum suppressors of chemotaxis, granulopoiesis, and ADCCC. Likewise, PMN's from anergic and skin test positive patients will be evaluated by ADCCC, chemotactic surface receptors, and their ability to enhance lymphocyte stimulation. The role of immunoglobulin classes and subclasses in suppression of PMN and lymphocyte ADCCC will also be evaluated and related to circulating immune complexes.